Len Gengel, a contractor from Massachusetts, and Dr. Paul Dougherty, a renowned Los Angeles ophthalmologist, may have come from completely different worlds, but a common mission to help others brought them both to earthquake-ravaged Haiti.

Both men had lost a child and felt a responsibility to honor their memories by using their skills to help rebuild Haiti -- and themselves.

"We are part of a club that no parent wants to be a part of," Gengel said.

Nearly three years ago, a devastating earthquake killed some 300,000 people in Haiti. Gengel's daughter Britney was one of them.

"Brit lit up a room," Gengel said. "She would walk into a room and she would light it up. She was spirited and she had a great personality and just loved people."

A student at Lynn University, Britney Gengel was in Port-au-Prince for a college service trip when the earthquake struck on Jan. 12, 2010. Her body was discovered a month later in the rubble of the Hotel Montana.

Since then, Len Gengel has made 28 trips to Haiti, and took a painful pilgrimage with "Nightline" back to the spot where Britney was found.

"The hardest thing I ever had to do was walk away from that pile knowing my daughter was underneath there," he said.

Just hours before her death, Gengel said, he received a text message from Britney, which said, "They love us so much and everyone is so happy. They love what they have and they work so hard to get nowhere, yet they are all so appreciative. I want to move here and start an orphanage myself."

Len Gengel didn't know it at the time, but that message would change the course of his life. After his daughter's death, Gengel and his wife, Cherylann, set up a foundation in her honor called Be Like Brit. They sold their house and used their own money to start building an orphanage in their daughter's memory. Friends and family pitched in with donations.

Local businesses helped with architectural plans and construction equipment. Gengel's goal is to build the orphanage to the same seismic standards used on buildings in San Francisco. To this end, the concrete is being routinely tested for its strength.

The site of the orphanage Gengel is building is in the gritty town of Grand Goave on Haiti's azure western coast, a place his daughter was scheduled to visit the week she was killed.

As a contractor for 30 years, Gengel has built hundreds of homes in the United States, but said this project was like no other.

"[It's] the greatest challenge in my homebuilding career ever," he said.

Gengel started construction on the orphanage in December 2010, and soon became the biggest employer in the area, hiring a 75-man crew in a country with 60 percent unemployment.

He had given up his dreams for his child's dreams. "That's what parents are supposed to do," Gengel said. "Any parent I know worth their salt, that's what they do."

That is what brought Dr. Paul Dougherty to Haiti as well. Several years ago, Dougherty's son Andrew died suddenly of the flu. He was just 5 years old.

"We think about him a lot," Dougherty said. "It's usually with a smile. He was a hilarious kid."

After Andrew's death, Dougherty started a foundation, World Vision Project, using his skills as an eye surgeon to travel around the world to perform desperately needed eye surgeries. Recently, Dougherty took his first trip to Haiti, where the need is great. There are only 50 ophthalmologists for nearly 10 million Haitians. His trip was made possible with the help of his Los Angeles team and donations of surgical equipment and supplies from all over the country.

Dougherty set up shop at Bernard Mevs Hospital in Port-au-Prince. Considered one of the top trauma centers in the country, the hospital is a rudimentary collection of buildings where the triage unit is under a tent, and guards carrying sawed-off shotguns stand watch over the crowds of people hoping to get inside the gates for treatment.